97 Tacoma Trade

i have a friend that wants to trade me their 97 tacoma for a car i have but the truck has an issue and i am not sure how much it will take to fix it.

It is a 97 with almost 200,000 miles on it. the truck has the 2.7 L engine in it. One of the middle spark plugs must have been put in cross threaded or something and when he was driving down the freeway it shot out and slamed the underside of the hood. Now the threads are stripped and a plug will not screw in. i bought a tap for the correct size and tried to straighten what is left of the threads but it did now work well enough to get a plug to screw in. my next guess is to install a heli-coil kit. i am guessing i would need to remove the engine head to do this correctly. also i believe there is a sleve that is pressed into something for the plug hole. i am just trying to figure out if it is worth my time to trade and fix this problem, or is the engine not really worth fixing because of the miles. i am trying to make this as cheap as possible but am open to suggestions. I have never removed a head from an engine before either so not sure how much work this is.

I'd look over the rest of the truck and see what its condition is. If its in good shape you can get a "new" engine from one of the Japanese engine resellers for a very good price. Search for them online. You can pick one up with less then 50k on it for under $1000 if the rest of your engine is ok.